ByApril AustinJuly 27, 2007

Many of us, as children, created tiny worlds out of dollhouses and sandboxes, or built miniature cities out of blocks. Making an object that looked as close to the full-size version as possible required ingenuity and imagination. Cutting the adult world down to size gave us a Master-of-the-Universe-size confidence and stimulated a desire to make our mark.

Miniature books fall into this category, but with added benefits. Not only does their small size (often measuring 3 inches or less) test the bookbinder's skill, but also, importantly for book lovers, it allowed for portability centuries before mass-market paperbacks were invented. Napoleon Bonaparte apparently never left home without an entire miniature library – of French classics, naturellement. Muslim soldiers fighting alongside the Allies in World War I were given tiny Korans, printed in Arabic by a Glasgow publisher, that could be worn like a locket around the neck. In England, young children were kept occupied during long church services with their very own illustrated "thumb" Bibles, the first of which appeared in 1727.

Examples of these magnificent small books can be seen in two concurrent exhibitions this summer, both titled "Miniature Books: 4,000 Years of Tiny Treasures," at the Boston Public Library and, ending July 28, at the Grolier Club in New York.

These books survive in large part due to collectors and also to a thoroughly knowledgeable expert, Anne Bromer. Mrs. Bromer and her husband, David, operate Bromer Booksellers in Boston, which carries antique and rare books. Mrs. Bromer and collector Julian Edison have gathered an impressive trove of miniature books, with one of the earliest examples being an inscribed Babylonian clay tablet from about 2325 BC., which measures 1-5/8 by 1-1/2 inches.

Other highlights include illuminated manuscripts from the 15th century, volumes with precious-metal and jewel-encrusted covers from 17th-century France, and a sliver of a book with drawings by Picasso from 1960.

Bromer and Mr. Edison have collaborated on a full-size book, also titled "Miniature Books: 4,000 Years of Tiny Treasures," which was published by Abrams in May. It provides beautiful actual-size photographs of volumes that appear in both exhibitions, along with rare examples from other famous collections.

On a rainy afternoon, Bromer welcomes a writer to her pleasant second-floor shop across the street from the Boston Public Library. The shop is half museum, half library; its walls are dotted with book-related artwork, and glass cases hold first editions and rare volumes. Bromer has laid out several thumb Bibles and other examples of miniature books, allowing them to be handled. These Bibles, made in the 1800s with middle-class families in mind, are remarkably sturdy, easy to read, and beautifully illustrated.

"We wanted to break the stereotype of miniature books being thought of as gimmicks," she says.

Not only did small volumes show off the skills of craftsmen, but their size also enabled them to be hidden. Jewish families for centuries relied on easily concealed prayer books to keep their faith alive in hostile lands. An English medical treatise on birth control, published 1832, became so popular it was reprinted at full size and was credited with helping drive down Britain's birthrate.

Bromer periodically stops by the library exhibition to greet visitors and share her enthusiasm for these Lilliputian masterpieces. Visitors peer into the cases with awe: Few have ever seen anything like these books, she says. They are amazed that the makers would lavish such care over small objects, and also that the texts are legible (although some require magnifying devices that were often cleverly housed in the covers).

She points out that the art of miniature books continues to be practiced today.

Every category covered in full-size books has its parallel in miniature, including children's literature, science, nature, religion, philosophy, politics, humor, travel, food, arts, and music. The first miniature books for children appeared in 1740, when a London bookseller, Thomas Boreman, began a series on noteworthy London architecture that he charmingly called "The Gigantick Histories."

"He was a great marketer," says Bromer, noting that Boreman produced the books in two-volume sets that he advertised would fit one in each of the child's pockets so that "there would be no fear of growing lopsided."

Visitors will wish they could carry home a few of these tempting little volumes in their pockets, to be thumbed through and enjoyed both for their artistry and for their piquant history.

• "Miniature Books: 4,000 Years of Tiny Treasures" is at the Grolier Club in New York through July 28 and at the Boston Public Library through Sept. 2. For additional information visitwww.bromer.comandwww.grolierclub.org.